forked from microsoft/TypeScript
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathparser.ts
More file actions
5538 lines (4880 loc) · 271 KB
/
Copy pathparser.ts
File metadata and controls
5538 lines (4880 loc) · 271 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/// <reference path="types.ts"/>
/// <reference path="core.ts"/>
/// <reference path="scanner.ts"/>
/// <reference path="utilities.ts"/>
module ts {
var nodeConstructors = new Array<new () => Node>(SyntaxKind.Count);
export function getNodeConstructor(kind: SyntaxKind): new () => Node {
return nodeConstructors[kind] || (nodeConstructors[kind] = objectAllocator.getNodeConstructor(kind));
}
export function createNode(kind: SyntaxKind): Node {
return new (getNodeConstructor(kind))();
}
// Invokes a callback for each child of the given node. The 'cbNode' callback is invoked for all child nodes
// stored in properties. If a 'cbNodes' callback is specified, it is invoked for embedded arrays; otherwise,
// embedded arrays are flattened and the 'cbNode' callback is invoked for each element. If a callback returns
// a truthy value, iteration stops and that value is returned. Otherwise, undefined is returned.
export function forEachChild<T>(node: Node, cbNode: (node: Node) => T, cbNodes?: (nodes: Node[]) => T): T {
function child(node: Node): T {
if (node) {
return cbNode(node);
}
}
function children(nodes: Node[]) {
if (nodes) {
if (cbNodes) {
return cbNodes(nodes);
}
for (var i = 0, len = nodes.length; i < len; i++) {
var result = cbNode(nodes[i])
if (result) {
return result;
}
}
return undefined;
}
}
if (!node) {
return;
}
switch (node.kind) {
case SyntaxKind.QualifiedName:
return child((<QualifiedName>node).left) ||
child((<QualifiedName>node).right);
case SyntaxKind.TypeParameter:
return child((<TypeParameterDeclaration>node).name) ||
child((<TypeParameterDeclaration>node).constraint);
case SyntaxKind.Parameter:
case SyntaxKind.PropertyDeclaration:
case SyntaxKind.PropertySignature:
case SyntaxKind.PropertyAssignment:
case SyntaxKind.ShorthandPropertyAssignment:
case SyntaxKind.VariableDeclaration:
case SyntaxKind.BindingElement:
return children(node.modifiers) ||
child((<VariableLikeDeclaration>node).propertyName) ||
child((<VariableLikeDeclaration>node).dotDotDotToken) ||
child((<VariableLikeDeclaration>node).name) ||
child((<VariableLikeDeclaration>node).questionToken) ||
child((<VariableLikeDeclaration>node).type) ||
child((<VariableLikeDeclaration>node).initializer);
case SyntaxKind.FunctionType:
case SyntaxKind.ConstructorType:
case SyntaxKind.CallSignature:
case SyntaxKind.ConstructSignature:
case SyntaxKind.IndexSignature:
return children(node.modifiers) ||
children((<SignatureDeclaration>node).typeParameters) ||
children((<SignatureDeclaration>node).parameters) ||
child((<SignatureDeclaration>node).type);
case SyntaxKind.MethodDeclaration:
case SyntaxKind.MethodSignature:
case SyntaxKind.Constructor:
case SyntaxKind.GetAccessor:
case SyntaxKind.SetAccessor:
case SyntaxKind.FunctionExpression:
case SyntaxKind.FunctionDeclaration:
case SyntaxKind.ArrowFunction:
return children(node.modifiers) ||
child((<FunctionLikeDeclaration>node).asteriskToken) ||
child((<FunctionLikeDeclaration>node).name) ||
child((<FunctionLikeDeclaration>node).questionToken) ||
children((<FunctionLikeDeclaration>node).typeParameters) ||
children((<FunctionLikeDeclaration>node).parameters) ||
child((<FunctionLikeDeclaration>node).type) ||
child((<FunctionLikeDeclaration>node).body);
case SyntaxKind.TypeReference:
return child((<TypeReferenceNode>node).typeName) ||
children((<TypeReferenceNode>node).typeArguments);
case SyntaxKind.TypeQuery:
return child((<TypeQueryNode>node).exprName);
case SyntaxKind.TypeLiteral:
return children((<TypeLiteralNode>node).members);
case SyntaxKind.ArrayType:
return child((<ArrayTypeNode>node).elementType);
case SyntaxKind.TupleType:
return children((<TupleTypeNode>node).elementTypes);
case SyntaxKind.UnionType:
return children((<UnionTypeNode>node).types);
case SyntaxKind.ParenthesizedType:
return child((<ParenthesizedTypeNode>node).type);
case SyntaxKind.ObjectBindingPattern:
case SyntaxKind.ArrayBindingPattern:
return children((<BindingPattern>node).elements);
case SyntaxKind.ArrayLiteralExpression:
return children((<ArrayLiteralExpression>node).elements);
case SyntaxKind.ObjectLiteralExpression:
return children((<ObjectLiteralExpression>node).properties);
case SyntaxKind.PropertyAccessExpression:
return child((<PropertyAccessExpression>node).expression) ||
child((<PropertyAccessExpression>node).name);
case SyntaxKind.ElementAccessExpression:
return child((<ElementAccessExpression>node).expression) ||
child((<ElementAccessExpression>node).argumentExpression);
case SyntaxKind.CallExpression:
case SyntaxKind.NewExpression:
return child((<CallExpression>node).expression) ||
children((<CallExpression>node).typeArguments) ||
children((<CallExpression>node).arguments);
case SyntaxKind.TaggedTemplateExpression:
return child((<TaggedTemplateExpression>node).tag) ||
child((<TaggedTemplateExpression>node).template);
case SyntaxKind.TypeAssertionExpression:
return child((<TypeAssertion>node).type) ||
child((<TypeAssertion>node).expression);
case SyntaxKind.ParenthesizedExpression:
return child((<ParenthesizedExpression>node).expression);
case SyntaxKind.DeleteExpression:
return child((<DeleteExpression>node).expression);
case SyntaxKind.TypeOfExpression:
return child((<TypeOfExpression>node).expression);
case SyntaxKind.VoidExpression:
return child((<VoidExpression>node).expression);
case SyntaxKind.PrefixUnaryExpression:
return child((<PrefixUnaryExpression>node).operand);
case SyntaxKind.YieldExpression:
return child((<YieldExpression>node).asteriskToken) ||
child((<YieldExpression>node).expression);
case SyntaxKind.PostfixUnaryExpression:
return child((<PostfixUnaryExpression>node).operand);
case SyntaxKind.BinaryExpression:
return child((<BinaryExpression>node).left) ||
child((<BinaryExpression>node).right);
case SyntaxKind.ConditionalExpression:
return child((<ConditionalExpression>node).condition) ||
child((<ConditionalExpression>node).whenTrue) ||
child((<ConditionalExpression>node).whenFalse);
case SyntaxKind.Block:
case SyntaxKind.TryBlock:
case SyntaxKind.FinallyBlock:
case SyntaxKind.ModuleBlock:
return children((<Block>node).statements);
case SyntaxKind.SourceFile:
return children((<SourceFile>node).statements) ||
child((<SourceFile>node).endOfFileToken);
case SyntaxKind.VariableStatement:
return children(node.modifiers) ||
children((<VariableStatement>node).declarations);
case SyntaxKind.ExpressionStatement:
return child((<ExpressionStatement>node).expression);
case SyntaxKind.IfStatement:
return child((<IfStatement>node).expression) ||
child((<IfStatement>node).thenStatement) ||
child((<IfStatement>node).elseStatement);
case SyntaxKind.DoStatement:
return child((<DoStatement>node).statement) ||
child((<DoStatement>node).expression);
case SyntaxKind.WhileStatement:
return child((<WhileStatement>node).expression) ||
child((<WhileStatement>node).statement);
case SyntaxKind.ForStatement:
return children((<ForStatement>node).declarations) ||
child((<ForStatement>node).initializer) ||
child((<ForStatement>node).condition) ||
child((<ForStatement>node).iterator) ||
child((<ForStatement>node).statement);
case SyntaxKind.ForInStatement:
return children((<ForInStatement>node).declarations) ||
child((<ForInStatement>node).variable) ||
child((<ForInStatement>node).expression) ||
child((<ForInStatement>node).statement);
case SyntaxKind.ContinueStatement:
case SyntaxKind.BreakStatement:
return child((<BreakOrContinueStatement>node).label);
case SyntaxKind.ReturnStatement:
return child((<ReturnStatement>node).expression);
case SyntaxKind.WithStatement:
return child((<WithStatement>node).expression) ||
child((<WithStatement>node).statement);
case SyntaxKind.SwitchStatement:
return child((<SwitchStatement>node).expression) ||
children((<SwitchStatement>node).clauses);
case SyntaxKind.CaseClause:
return child((<CaseClause>node).expression) ||
children((<CaseClause>node).statements);
case SyntaxKind.DefaultClause:
return children((<DefaultClause>node).statements);
case SyntaxKind.LabeledStatement:
return child((<LabeledStatement>node).label) ||
child((<LabeledStatement>node).statement);
case SyntaxKind.ThrowStatement:
return child((<ThrowStatement>node).expression);
case SyntaxKind.TryStatement:
return child((<TryStatement>node).tryBlock) ||
child((<TryStatement>node).catchClause) ||
child((<TryStatement>node).finallyBlock);
case SyntaxKind.CatchClause:
return child((<CatchClause>node).name) ||
child((<CatchClause>node).type) ||
child((<CatchClause>node).block);
case SyntaxKind.ClassDeclaration:
return children(node.modifiers) ||
child((<ClassDeclaration>node).name) ||
children((<ClassDeclaration>node).typeParameters) ||
children((<ClassDeclaration>node).heritageClauses) ||
children((<ClassDeclaration>node).members);
case SyntaxKind.InterfaceDeclaration:
return children(node.modifiers) ||
child((<InterfaceDeclaration>node).name) ||
children((<InterfaceDeclaration>node).typeParameters) ||
children((<ClassDeclaration>node).heritageClauses) ||
children((<InterfaceDeclaration>node).members);
case SyntaxKind.TypeAliasDeclaration:
return children(node.modifiers) ||
child((<TypeAliasDeclaration>node).name) ||
child((<TypeAliasDeclaration>node).type);
case SyntaxKind.EnumDeclaration:
return children(node.modifiers) ||
child((<EnumDeclaration>node).name) ||
children((<EnumDeclaration>node).members);
case SyntaxKind.EnumMember:
return child((<EnumMember>node).name) ||
child((<EnumMember>node).initializer);
case SyntaxKind.ModuleDeclaration:
return children(node.modifiers) ||
child((<ModuleDeclaration>node).name) ||
child((<ModuleDeclaration>node).body);
case SyntaxKind.ImportDeclaration:
return children(node.modifiers) ||
child((<ImportDeclaration>node).name) ||
child((<ImportDeclaration>node).moduleReference);
case SyntaxKind.ExportAssignment:
return children(node.modifiers) ||
child((<ExportAssignment>node).exportName);
case SyntaxKind.TemplateExpression:
return child((<TemplateExpression>node).head) || children((<TemplateExpression>node).templateSpans);
case SyntaxKind.TemplateSpan:
return child((<TemplateSpan>node).expression) || child((<TemplateSpan>node).literal);
case SyntaxKind.ComputedPropertyName:
return child((<ComputedPropertyName>node).expression);
case SyntaxKind.HeritageClause:
return children((<HeritageClause>node).types);
case SyntaxKind.ExternalModuleReference:
return child((<ExternalModuleReference>node).expression);
}
}
// TODO (drosen, mhegazy): Move to a more appropriate file.
export function createCompilerHost(options: CompilerOptions): CompilerHost {
var currentDirectory: string;
var existingDirectories: Map<boolean> = {};
function getCanonicalFileName(fileName: string): string {
// if underlying system can distinguish between two files whose names differs only in cases then file name already in canonical form.
// otherwise use toLowerCase as a canonical form.
return sys.useCaseSensitiveFileNames ? fileName : fileName.toLowerCase();
}
// returned by CScript sys environment
var unsupportedFileEncodingErrorCode = -2147024809;
function getSourceFile(filename: string, languageVersion: ScriptTarget, onError?: (message: string) => void): SourceFile {
try {
var text = sys.readFile(filename, options.charset);
}
catch (e) {
if (onError) {
onError(e.number === unsupportedFileEncodingErrorCode ?
createCompilerDiagnostic(Diagnostics.Unsupported_file_encoding).messageText :
e.message);
}
text = "";
}
return text !== undefined ? createSourceFile(filename, text, languageVersion) : undefined;
}
function writeFile(fileName: string, data: string, writeByteOrderMark: boolean, onError?: (message: string) => void) {
function directoryExists(directoryPath: string): boolean {
if (hasProperty(existingDirectories, directoryPath)) {
return true;
}
if (sys.directoryExists(directoryPath)) {
existingDirectories[directoryPath] = true;
return true;
}
return false;
}
function ensureDirectoriesExist(directoryPath: string) {
if (directoryPath.length > getRootLength(directoryPath) && !directoryExists(directoryPath)) {
var parentDirectory = getDirectoryPath(directoryPath);
ensureDirectoriesExist(parentDirectory);
sys.createDirectory(directoryPath);
}
}
try {
ensureDirectoriesExist(getDirectoryPath(normalizePath(fileName)));
sys.writeFile(fileName, data, writeByteOrderMark);
}
catch (e) {
if (onError) {
onError(e.message);
}
}
}
return {
getSourceFile,
getDefaultLibFilename: options => combinePaths(getDirectoryPath(normalizePath(sys.getExecutingFilePath())), options.target === ScriptTarget.ES6 ? "lib.es6.d.ts" : "lib.d.ts"),
writeFile,
getCurrentDirectory: () => currentDirectory || (currentDirectory = sys.getCurrentDirectory()),
useCaseSensitiveFileNames: () => sys.useCaseSensitiveFileNames,
getCanonicalFileName,
getNewLine: () => sys.newLine
};
}
const enum ParsingContext {
SourceElements, // Elements in source file
ModuleElements, // Elements in module declaration
BlockStatements, // Statements in block
SwitchClauses, // Clauses in switch statement
SwitchClauseStatements, // Statements in switch clause
TypeMembers, // Members in interface or type literal
ClassMembers, // Members in class declaration
EnumMembers, // Members in enum declaration
TypeReferences, // Type references in extends or implements clause
VariableDeclarations, // Variable declarations in variable statement
ObjectBindingElements, // Binding elements in object binding list
ArrayBindingElements, // Binding elements in array binding list
ArgumentExpressions, // Expressions in argument list
ObjectLiteralMembers, // Members in object literal
ArrayLiteralMembers, // Members in array literal
Parameters, // Parameters in parameter list
TypeParameters, // Type parameters in type parameter list
TypeArguments, // Type arguments in type argument list
TupleElementTypes, // Element types in tuple element type list
HeritageClauses, // Heritage clauses for a class or interface declaration.
Count // Number of parsing contexts
}
const enum Tristate {
False,
True,
Unknown
}
function parsingContextErrors(context: ParsingContext): DiagnosticMessage {
switch (context) {
case ParsingContext.SourceElements: return Diagnostics.Declaration_or_statement_expected;
case ParsingContext.ModuleElements: return Diagnostics.Declaration_or_statement_expected;
case ParsingContext.BlockStatements: return Diagnostics.Statement_expected;
case ParsingContext.SwitchClauses: return Diagnostics.case_or_default_expected;
case ParsingContext.SwitchClauseStatements: return Diagnostics.Statement_expected;
case ParsingContext.TypeMembers: return Diagnostics.Property_or_signature_expected;
case ParsingContext.ClassMembers: return Diagnostics.Unexpected_token_A_constructor_method_accessor_or_property_was_expected;
case ParsingContext.EnumMembers: return Diagnostics.Enum_member_expected;
case ParsingContext.TypeReferences: return Diagnostics.Type_reference_expected;
case ParsingContext.VariableDeclarations: return Diagnostics.Variable_declaration_expected;
case ParsingContext.ObjectBindingElements: return Diagnostics.Property_destructuring_pattern_expected;
case ParsingContext.ArrayBindingElements: return Diagnostics.Array_element_destructuring_pattern_expected;
case ParsingContext.ArgumentExpressions: return Diagnostics.Argument_expression_expected;
case ParsingContext.ObjectLiteralMembers: return Diagnostics.Property_assignment_expected;
case ParsingContext.ArrayLiteralMembers: return Diagnostics.Expression_or_comma_expected;
case ParsingContext.Parameters: return Diagnostics.Parameter_declaration_expected;
case ParsingContext.TypeParameters: return Diagnostics.Type_parameter_declaration_expected;
case ParsingContext.TypeArguments: return Diagnostics.Type_argument_expected;
case ParsingContext.TupleElementTypes: return Diagnostics.Type_expected;
case ParsingContext.HeritageClauses: return Diagnostics.Unexpected_token_expected;
}
};
function modifierToFlag(token: SyntaxKind): NodeFlags {
switch (token) {
case SyntaxKind.StaticKeyword: return NodeFlags.Static;
case SyntaxKind.PublicKeyword: return NodeFlags.Public;
case SyntaxKind.ProtectedKeyword: return NodeFlags.Protected;
case SyntaxKind.PrivateKeyword: return NodeFlags.Private;
case SyntaxKind.ExportKeyword: return NodeFlags.Export;
case SyntaxKind.DeclareKeyword: return NodeFlags.Ambient;
case SyntaxKind.ConstKeyword: return NodeFlags.Const;
}
return 0;
}
function fixupParentReferences(sourceFile: SourceFile) {
// normally parent references are set during binding.
// however here SourceFile data is used only for syntactic features so running the whole binding process is an overhead.
// walk over the nodes and set parent references
var parent: Node = sourceFile;
function walk(n: Node): void {
// walk down setting parents that differ from the parent we think it should be. This
// allows us to quickly bail out of setting parents for subtrees during incremental
// parsing
if (n.parent !== parent) {
n.parent = parent;
var saveParent = parent;
parent = n;
forEachChild(n, walk);
parent = saveParent;
}
}
forEachChild(sourceFile, walk);
}
function isEvalOrArgumentsIdentifier(node: Node): boolean {
return node.kind === SyntaxKind.Identifier &&
((<Identifier>node).text === "eval" || (<Identifier>node).text === "arguments");
}
/// Should be called only on prologue directives (isPrologueDirective(node) should be true)
function isUseStrictPrologueDirective(sourceFile: SourceFile, node: Node): boolean {
Debug.assert(isPrologueDirective(node));
var nodeText = getSourceTextOfNodeFromSourceFile(sourceFile,(<ExpressionStatement>node).expression);
return nodeText === '"use strict"' || nodeText === "'use strict'";
}
export function createSourceFile(filename: string, sourceText: string, languageVersion: ScriptTarget, setParentNodes = false): SourceFile {
var parsingContext: ParsingContext;
var identifiers: Map<string> = {};
var identifierCount = 0;
var nodeCount = 0;
var lineStarts: number[];
// Flags that dictate what parsing context we're in. For example:
// Whether or not we are in strict parsing mode. All that changes in strict parsing mode is
// that some tokens that would be considered identifiers may be considered keywords.
//
// When adding more parser context flags, consider which is the more common case that the
// flag will be in. This should be hte 'false' state for that flag. The reason for this is
// that we don't store data in our nodes unless the value is in the *non-default* state. So,
// for example, more often than code 'allows-in' (or doesn't 'disallow-in'). We opt for
// 'disallow-in' set to 'false'. Otherwise, if we had 'allowsIn' set to 'true', then almost
// all nodes would need extra state on them to store this info.
//
// Note: 'allowIn' and 'allowYield' track 1:1 with the [in] and [yield] concepts in the ES6
// grammar specification.
//
// An important thing about these context concepts. By default they are effectively inherited
// while parsing through every grammar production. i.e. if you don't change them, then when
// you parse a sub-production, it will have the same context values as hte parent production.
// This is great most of the time. After all, consider all the 'expression' grammar productions
// and how nearly all of them pass along the 'in' and 'yield' context values:
//
// EqualityExpression[In, Yield] :
// RelationalExpression[?In, ?Yield]
// EqualityExpression[?In, ?Yield] == RelationalExpression[?In, ?Yield]
// EqualityExpression[?In, ?Yield] != RelationalExpression[?In, ?Yield]
// EqualityExpression[?In, ?Yield] === RelationalExpression[?In, ?Yield]
// EqualityExpression[?In, ?Yield] !== RelationalExpression[?In, ?Yield]
//
// Where you have to be careful is then understanding what the points are in the grammar
// where the values are *not* passed along. For example:
//
// SingleNameBinding[Yield,GeneratorParameter]
// [+GeneratorParameter]BindingIdentifier[Yield] Initializer[In]opt
// [~GeneratorParameter]BindingIdentifier[?Yield]Initializer[In, ?Yield]opt
//
// Here this is saying that if the GeneratorParameter context flag is set, that we should
// explicitly set the 'yield' context flag to false before calling into the BindingIdentifier
// and we should explicitly unset the 'yield' context flag before calling into the Initializer.
// production. Conversely, if the GeneratorParameter context flag is not set, then we
// should leave the 'yield' context flag alone.
//
// Getting this all correct is tricky and requires careful reading of the grammar to
// understand when these values should be changed versus when they should be inherited.
//
// Note: it should not be necessary to save/restore these flags during speculative/lookahead
// parsing. These context flags are naturally stored and restored through normal recursive
// descent parsing and unwinding.
var contextFlags: ParserContextFlags = 0;
// Whether or not we've had a parse error since creating the last AST node. If we have
// encountered an error, it will be stored on the next AST node we create. Parse errors
// can be broken down into three categories:
//
// 1) An error that occurred during scanning. For example, an unterminated literal, or a
// character that was completely not understood.
//
// 2) A token was expected, but was not present. This type of error is commonly produced
// by the 'parseExpected' function.
//
// 3) A token was present that no parsing function was able to consume. This type of error
// only occurs in the 'abortParsingListOrMoveToNextToken' function when the parser
// decides to skip the token.
//
// In all of these cases, we want to mark the next node as having had an error before it.
// With this mark, we can know in incremental settings if this node can be reused, or if
// we have to reparse it. If we don't keep this information around, we may just reuse the
// node. in that event we would then not produce the same errors as we did before, causing
// significant confusion problems.
//
// Note: it is necessary that this value be saved/restored during speculative/lookahead
// parsing. During lookahead parsing, we will often create a node. That node will have
// this value attached, and then this value will be set back to 'false'. If we decide to
// rewind, we must get back to the same value we had prior to the lookahead.
//
// Note: any errors at the end of the file that do not precede a regular node, should get
// attached to the EOF token.
var parseErrorBeforeNextFinishedNode = false;
var sourceFile = <SourceFile>createNode(SyntaxKind.SourceFile, 0);
if (fileExtensionIs(filename, ".d.ts")) {
sourceFile.flags = NodeFlags.DeclarationFile;
}
sourceFile.end = sourceText.length;
sourceFile.filename = normalizePath(filename);
sourceFile.text = sourceText;
sourceFile.getLineAndCharacterFromPosition = getLineAndCharacterFromSourcePosition;
sourceFile.getPositionFromLineAndCharacter = getPositionFromSourceLineAndCharacter;
sourceFile.getLineStarts = getLineStarts;
sourceFile.getSyntacticDiagnostics = getSyntacticDiagnostics;
sourceFile.referenceDiagnostics = [];
sourceFile.parseDiagnostics = [];
sourceFile.grammarDiagnostics = [];
sourceFile.semanticDiagnostics = [];
processReferenceComments();
// Create and prime the scanner before parsing the source elements.
var scanner = createScanner(languageVersion, /*skipTrivia*/ true, sourceText, scanError);
var token = nextToken();
sourceFile.statements = parseList(ParsingContext.SourceElements, /*checkForStrictMode*/ true, parseSourceElement);
Debug.assert(token === SyntaxKind.EndOfFileToken);
sourceFile.endOfFileToken = parseTokenNode();
sourceFile.externalModuleIndicator = getExternalModuleIndicator();
sourceFile.nodeCount = nodeCount;
sourceFile.identifierCount = identifierCount;
sourceFile.languageVersion = languageVersion;
sourceFile.identifiers = identifiers;
if (setParentNodes) {
fixupParentReferences(sourceFile);
}
return sourceFile;
function setContextFlag(val: Boolean, flag: ParserContextFlags) {
if (val) {
contextFlags |= flag;
}
else {
contextFlags &= ~flag;
}
}
function setStrictModeContext(val: boolean) {
setContextFlag(val, ParserContextFlags.StrictMode);
}
function setDisallowInContext(val: boolean) {
setContextFlag(val, ParserContextFlags.DisallowIn);
}
function setYieldContext(val: boolean) {
setContextFlag(val, ParserContextFlags.Yield);
}
function setGeneratorParameterContext(val: boolean) {
setContextFlag(val, ParserContextFlags.GeneratorParameter);
}
function allowInAnd<T>(func: () => T): T {
if (contextFlags & ParserContextFlags.DisallowIn) {
setDisallowInContext(false);
var result = func();
setDisallowInContext(true);
return result;
}
// no need to do anything special if 'in' is already allowed.
return func();
}
function disallowInAnd<T>(func: () => T): T {
if (contextFlags & ParserContextFlags.DisallowIn) {
// no need to do anything special if 'in' is already disallowed.
return func();
}
setDisallowInContext(true);
var result = func();
setDisallowInContext(false);
return result;
}
function doInYieldContext<T>(func: () => T): T {
if (contextFlags & ParserContextFlags.Yield) {
// no need to do anything special if we're already in the [Yield] context.
return func();
}
setYieldContext(true);
var result = func();
setYieldContext(false);
return result;
}
function doOutsideOfYieldContext<T>(func: () => T): T {
if (contextFlags & ParserContextFlags.Yield) {
setYieldContext(false);
var result = func();
setYieldContext(true);
return result;
}
// no need to do anything special if we're not in the [Yield] context.
return func();
}
function inYieldContext() {
return (contextFlags & ParserContextFlags.Yield) !== 0;
}
function inStrictModeContext() {
return (contextFlags & ParserContextFlags.StrictMode) !== 0;
}
function inGeneratorParameterContext() {
return (contextFlags & ParserContextFlags.GeneratorParameter) !== 0;
}
function inDisallowInContext() {
return (contextFlags & ParserContextFlags.DisallowIn) !== 0;
}
function getLineStarts(): number[] {
return lineStarts || (lineStarts = computeLineStarts(sourceText));
}
function getLineAndCharacterFromSourcePosition(position: number) {
return getLineAndCharacterOfPosition(getLineStarts(), position);
}
function getPositionFromSourceLineAndCharacter(line: number, character: number): number {
return getPositionFromLineAndCharacter(getLineStarts(), line, character);
}
function parseErrorAtCurrentToken(message: DiagnosticMessage, arg0?: any): void {
var start = scanner.getTokenPos();
var length = scanner.getTextPos() - start;
parseErrorAtPosition(start, length, message, arg0);
}
function parseErrorAtPosition(start: number, length: number, message: DiagnosticMessage, arg0?: any): void {
// Don't report another error if it would just be at the same position as the last error.
var lastError = lastOrUndefined(sourceFile.parseDiagnostics);
if (!lastError || start !== lastError.start) {
sourceFile.parseDiagnostics.push(createFileDiagnostic(sourceFile, start, length, message, arg0));
}
// Mark that we've encountered an error. We'll set an appropriate bit on the next
// node we finish so that it can't be reused incrementally.
parseErrorBeforeNextFinishedNode = true;
}
function scanError(message: DiagnosticMessage) {
var pos = scanner.getTextPos();
parseErrorAtPosition(pos, 0, message);
}
function getNodePos(): number {
return scanner.getStartPos();
}
function getNodeEnd(): number {
return scanner.getStartPos();
}
function nextToken(): SyntaxKind {
return token = scanner.scan();
}
function getTokenPos(pos: number): number {
return skipTrivia(sourceText, pos);
}
function reScanGreaterToken(): SyntaxKind {
return token = scanner.reScanGreaterToken();
}
function reScanSlashToken(): SyntaxKind {
return token = scanner.reScanSlashToken();
}
function reScanTemplateToken(): SyntaxKind {
return token = scanner.reScanTemplateToken();
}
function speculationHelper<T>(callback: () => T, isLookAhead: boolean): T {
// Keep track of the state we'll need to rollback to if lookahead fails (or if the
// caller asked us to always reset our state).
var saveToken = token;
var saveParseDiagnosticsLength = sourceFile.parseDiagnostics.length;
var saveParseErrorBeforeNextFinishedNode = parseErrorBeforeNextFinishedNode;
// Note: it is not actually necessary to save/restore the context flags here. That's
// because the saving/restorating of these flags happens naturally through the recursive
// descent nature of our parser. However, we still store this here just so we can
// assert that that invariant holds.
var saveContextFlags = contextFlags;
// If we're only looking ahead, then tell the scanner to only lookahead as well.
// Otherwise, if we're actually speculatively parsing, then tell the scanner to do the
// same.
var result = isLookAhead
? scanner.lookAhead(callback)
: scanner.tryScan(callback);
Debug.assert(saveContextFlags === contextFlags);
// If our callback returned something 'falsy' or we're just looking ahead,
// then unconditionally restore us to where we were.
if (!result || isLookAhead) {
token = saveToken;
sourceFile.parseDiagnostics.length = saveParseDiagnosticsLength;
parseErrorBeforeNextFinishedNode = saveParseErrorBeforeNextFinishedNode;
}
return result;
}
// Invokes the provided callback then unconditionally restores the parser to the state it
// was in immediately prior to invoking the callback. The result of invoking the callback
// is returned from this function.
function lookAhead<T>(callback: () => T): T {
return speculationHelper(callback, /*isLookAhead:*/ true);
}
// Invokes the provided callback. If the callback returns something falsy, then it restores
// the parser to the state it was in immediately prior to invoking the callback. If the
// callback returns something truthy, then the parser state is not rolled back. The result
// of invoking the callback is returned from this function.
function tryParse<T>(callback: () => T): T {
return speculationHelper(callback, /*isLookAhead:*/ false);
}
function isIdentifier(): boolean {
if (token === SyntaxKind.Identifier) {
return true;
}
// If we have a 'yield' keyword, and we're in the [yield] context, then 'yield' is
// considered a keyword and is not an identifier.
if (token === SyntaxKind.YieldKeyword && inYieldContext()) {
return false;
}
return inStrictModeContext() ? token > SyntaxKind.LastFutureReservedWord : token > SyntaxKind.LastReservedWord;
}
function parseExpected(kind: SyntaxKind, diagnosticMessage?: DiagnosticMessage, arg0?: any): boolean {
if (token === kind) {
nextToken();
return true;
}
// Report specific message if provided with one. Otherwise, report generic fallback message.
if (diagnosticMessage) {
parseErrorAtCurrentToken(diagnosticMessage, arg0);
}
else {
parseErrorAtCurrentToken(Diagnostics._0_expected, tokenToString(kind));
}
return false;
}
function parseOptional(t: SyntaxKind): boolean {
if (token === t) {
nextToken();
return true;
}
return false;
}
function parseOptionalToken(t: SyntaxKind): Node {
if (token === t) {
var node = createNode(t);
nextToken();
return finishNode(node);
}
return undefined;
}
function canParseSemicolon() {
// If there's a real semicolon, then we can always parse it out.
if (token === SyntaxKind.SemicolonToken) {
return true;
}
// We can parse out an optional semicolon in ASI cases in the following cases.
return token === SyntaxKind.CloseBraceToken || token === SyntaxKind.EndOfFileToken || scanner.hasPrecedingLineBreak();
}
function parseSemicolon(diagnosticMessage?: DiagnosticMessage): boolean {
if (canParseSemicolon()) {
if (token === SyntaxKind.SemicolonToken) {
// consume the semicolon if it was explicitly provided.
nextToken();
}
return true;
}
else {
return parseExpected(SyntaxKind.SemicolonToken, diagnosticMessage);
}
}
function createNode(kind: SyntaxKind, pos?: number): Node {
nodeCount++;
var node = new (nodeConstructors[kind] || (nodeConstructors[kind] = objectAllocator.getNodeConstructor(kind)))();
if (!(pos >= 0)) {
pos = scanner.getStartPos();
}
node.pos = pos;
node.end = pos;
return node;
}
function finishNode<T extends Node>(node: T): T {
node.end = scanner.getStartPos();
if (contextFlags) {
node.parserContextFlags = contextFlags;
}
// Keep track on the node if we encountered an error while parsing it. If we did, then
// we cannot reuse the node incrementally. Once we've marked this node, clear out the
// flag so that we don't mark any subsequent nodes.
if (parseErrorBeforeNextFinishedNode) {
parseErrorBeforeNextFinishedNode = false;
node.parserContextFlags |= ParserContextFlags.ThisNodeHasError;
}
return node;
}
function createMissingNode(kind: SyntaxKind, reportAtCurrentPosition: boolean, diagnosticMessage: DiagnosticMessage, arg0?: any): Node {
if (reportAtCurrentPosition) {
parseErrorAtPosition(scanner.getStartPos(), 0, diagnosticMessage, arg0);
}
else {
parseErrorAtCurrentToken(diagnosticMessage, arg0);
}
var result = createNode(kind, scanner.getStartPos());
(<Identifier>result).text = "";
return finishNode(result);
}
function internIdentifier(text: string): string {
text = escapeIdentifier(text);
return hasProperty(identifiers, text) ? identifiers[text] : (identifiers[text] = text);
}
// An identifier that starts with two underscores has an extra underscore character prepended to it to avoid issues
// with magic property names like '__proto__'. The 'identifiers' object is used to share a single string instance for
// each identifier in order to reduce memory consumption.
function createIdentifier(isIdentifier: boolean, diagnosticMessage?: DiagnosticMessage): Identifier {
identifierCount++;
if (isIdentifier) {
var node = <Identifier>createNode(SyntaxKind.Identifier);
node.text = internIdentifier(scanner.getTokenValue());
nextToken();
return finishNode(node);
}
return <Identifier>createMissingNode(SyntaxKind.Identifier, /*reportAtCurrentPosition:*/ false, diagnosticMessage || Diagnostics.Identifier_expected);
}
function parseIdentifier(diagnosticMessage?: DiagnosticMessage): Identifier {
return createIdentifier(isIdentifier(), diagnosticMessage);
}
function parseIdentifierName(): Identifier {
return createIdentifier(isIdentifierOrKeyword());
}
function isLiteralPropertyName(): boolean {
return isIdentifierOrKeyword() ||
token === SyntaxKind.StringLiteral ||
token === SyntaxKind.NumericLiteral;
}
function parsePropertyName(): DeclarationName {
if (token === SyntaxKind.StringLiteral || token === SyntaxKind.NumericLiteral) {
return parseLiteralNode(/*internName:*/ true);
}
if (token === SyntaxKind.OpenBracketToken) {
return parseComputedPropertyName();
}
return parseIdentifierName();
}
function parseComputedPropertyName(): ComputedPropertyName {
// PropertyName[Yield,GeneratorParameter] :
// LiteralPropertyName
// [+GeneratorParameter] ComputedPropertyName
// [~GeneratorParameter] ComputedPropertyName[?Yield]
//
// ComputedPropertyName[Yield] :
// [ AssignmentExpression[In, ?Yield] ]
//
var node = <ComputedPropertyName>createNode(SyntaxKind.ComputedPropertyName);
parseExpected(SyntaxKind.OpenBracketToken);
// We parse any expression (including a comma expression). But the grammar
// says that only an assignment expression is allowed, so the grammar checker
// will error if it sees a comma expression.
var yieldContext = inYieldContext();
if (inGeneratorParameterContext()) {
setYieldContext(false);
}
node.expression = allowInAnd(parseExpression);
if (inGeneratorParameterContext()) {
setYieldContext(yieldContext);
}
parseExpected(SyntaxKind.CloseBracketToken);
return finishNode(node);
}
function parseContextualModifier(t: SyntaxKind): boolean {
return token === t && tryParse(nextTokenCanFollowModifier);
}
function nextTokenCanFollowModifier() {
nextToken();
return canFollowModifier();
}
function parseAnyContextualModifier(): boolean {
return isModifier(token) && tryParse(nextTokenCanFollowContextualModifier);
}
function nextTokenCanFollowContextualModifier() {
if (token === SyntaxKind.ConstKeyword) {
// 'const' is only a modifier if followed by 'enum'.
return nextToken() === SyntaxKind.EnumKeyword;
}
nextToken();
return canFollowModifier();
}
function canFollowModifier(): boolean {
return token === SyntaxKind.OpenBracketToken || token === SyntaxKind.AsteriskToken || isLiteralPropertyName();
}
// True if positioned at the start of a list element
function isListElement(kind: ParsingContext, inErrorRecovery: boolean): boolean {
switch (kind) {
case ParsingContext.SourceElements:
case ParsingContext.ModuleElements:
return isSourceElement(inErrorRecovery);
case ParsingContext.BlockStatements:
case ParsingContext.SwitchClauseStatements:
return isStatement(inErrorRecovery);
case ParsingContext.SwitchClauses:
return token === SyntaxKind.CaseKeyword || token === SyntaxKind.DefaultKeyword;
case ParsingContext.TypeMembers:
return isStartOfTypeMember();
case ParsingContext.ClassMembers:
return lookAhead(isClassMemberStart);
case ParsingContext.EnumMembers:
// Include open bracket computed properties. This technically also lets in indexers,
// which would be a candidate for improved error reporting.
return token === SyntaxKind.OpenBracketToken || isLiteralPropertyName();
case ParsingContext.ObjectLiteralMembers:
return token === SyntaxKind.OpenBracketToken || token === SyntaxKind.AsteriskToken || isLiteralPropertyName();
case ParsingContext.ObjectBindingElements:
return isLiteralPropertyName();